مروری بر کاتالیست‌های برپایۀ ایروژل‌های سیلیکایی

نویسندگان

1 دانشگاه زنجان

2 دانشگاه صنعتی سهند

چکیده

ایروژلهای سیلیکایی بهدلیل داشتن سطح ویژه و تخلخل بازِ بسیار بالابهعنوان
پایه کاتالیست­ها مورد توجه قرار گرفته­اند. در مقالۀ پیش رو کاتالیست­های بر پایۀ ایروژل‌های سیلیکایی مرور شده­اند. روش ساخت ایروژل­ها و روش­های گوناگون افزودن فاز فعال کاتالیستی در ماتریس ایروژلی توصیف شده
است. همنهشت ایروژل شامل تهیۀ ژل سیلیکا با فرایند سل-ژل و سپس خشککردن ژل با فنون ویژه برای رسیدن به ایروژل است. برای تهیۀ ایروژل کاتالیستی فاز دوم می­تواند پیش از تشکیل ژل و یا بعد از تشکیل ژل به آن افزوده شود. در روش اول محلول پیش­ماده­های فاز دوم و یا نانوذرات آن به
 سل سیلیکا افزوده می‌شود و فاز کاتالیستی همزمان با تشکیل ژل سیلیکا وارد ساختار آن می­شود. در روش دوم، فاز دوم بر روی ژل سیلیکا تلقیح می‌شود و یا به روش تلقیح یا نفوذ بخار بر روی ایروژل نشانده می­شود. مطالعات گوناگون انجام گرفته در زمینۀ ایروژل­های کاتالیستی گرداوری شده و واکنش مطالعه
شده به همراه روش خشک­سازی ایروژل،
پیش­مادۀ مورد استفاده برای سیلیکا و نیز روش تهیۀ کاتالیست در آنها ارائه شده
است. در پایان مقایسه­ای بین کاتالیست­های ایروژلی و زروژلی انجام شده‌است که مطالعات موجود نشان‌دهندۀ خواص مطلوبتر و عملکرد بسیار بهتر کاتالیست­های ایروژلی در واکنش­های گوناگون بودند. بهعنوان نمونه در مطالعات گوناگون، سطح ویژه تا 9/3 برابر بزرگتر، حجم تخلخل تا 23 برابر بزرگتر، میزان تبدیل واکنش­دهندۀ مد نظر تا 5/7 برابر بزرگتر، بازده محصول مد نظر تا 7 برابر بزرگتر و انتخاب­پذیری محصول دلخواه تا 4 برابر بیشتر برای کاتالیست ایروژلی نسبت به کاتالیست زروژلی گزارش شده است.

کلیدواژه‌ها


عنوان مقاله [English]

A Review on the Silica Aerogels-Supported Catalysts

نویسندگان [English]

  • T. Yousefi Amiri 1
  • H. Bargozin 1
  • J. S. Moghaddas 2
1 University of Zanjan
2 Sahand University of Technology
چکیده [English]

Silica aerogels are attractive candidates as catalyst support due to their very large surface area and high open porosity. This paper reviews the silica aerogel supported catalysts. General methods of silica aerogel synthesis and catalytic phase incorporation into aerogel matrix described. Aerogel synthesis consists of two main steps: wet gel preparation and drying the gel to obtain aerogel. Catalytic active phase can be added before or after silica gel formation. In the first approach, active phase precursor or as-prepared nanoparticles added to silica precursor. Active phase introduced into matrix structure during the gelation of matrix. In the second approach, active phase either impregnated on the silica wet gel or deposited on the aerogel by impregnation or vapor infiltration. Aerogel catalysts synthesis and aerogel drying methods, and used silica precursor as well as the studied reactions in the catalytic application of silica aerogel have been collected. Finally, a comparison between the properties and performance of the aerogel and xerogel catalyst have been presented which results confirm the favorable properties and better performance of aerogel catalysts in comparison with xerogel catalysts. As typical results in different studies, for aerogel catalyst the specific surface area up to 3.9 times larger, the pore volume up to 23 times larger, the reactant conversion up to 7.5 times larger, the product yield up to 7 times larger, and the desired product selectivity up to 4 times larger than those for xerogel catalyst have been obtained.

کلیدواژه‌ها [English]

  • aerogel
  • Catalyst
  • Synthesis
  • Properties
  • performance

 

[1]        Casas, L., Roig, A., Rodriguez, E., Molins, E., Tejada, J., Sort, J., "Silica Aerogel-Iron Oxide Nanocomposites: Structural and Magnetic Properties", Journal of Non-Crystalline Solids, 285, pp. 37-43, (2001).
[2]        Fabrizioli, P., Burgi, T., Baiker, A., "Environmental Catalysis on Iron Oxide–Silica Aerogels: Selective Oxidation of NH3 and Reduction of NO by NH3", Journal of Catalysis, 206, pp. 143–154, (2002).
[3]        Dunn, B. C., Cole, P., Covington, D., Webster, M. C., Pugmire, R. J., Ernst, R. D., Eyring, E. M., Shah,N., Huffman, G. P., "Silica Aerogel Supported Catalysts for Fischer–Tropsch Synthesis", Applied Catalysis A: General, 278, pp. 233–23, (2005).
[4]        Wang, C. -T., Ro, S. -H., "Nanocluster Iron Oxide-Silica Aerogel Catalysts for Methanol Partial Oxidation", Applied Catalysis A: General, 285,
pp. 196–204, (2005).
[5]        Dominguez, M., Taboada, E., Molins, E., Llorca, J., "Co–SiO2 Aerogel-Coated Catalytic Walls for the Generation of Hydrogen", Catalysis Today, 138,
pp. 193-197,  (2008).
[6]        Gurav, J. L., Jung, I., -K., Park, H. -H., Kang, E. S., Nadargi, D. Y., "Silica Aerogel: Synthesis and Applications", Journal of Nanomaterials, 2010,
pp. 1-11, (2010).
[7]        Yousefi Amiri, T., Moghaddas, J. S., Rahmani Khajeh, S., "Silica Aerogel-Supported Copper Catalyst Prepared via Ambient Pressure Drying Process", Journal of Sol-Gel Science and Technology, 77, pp. 627-635, (2016).
 [8]       Aegerter, M. A., Leventis, N., Koebel, M. M., " Aerogels Handbook", New York, Springer, (2011).
[9]        Martinez, S., Meseguer, M., Casas, L., Rodriguez, E., Molins, E., Moreno-Manas, M., Roig, A.,Rosa MSebastián, R. M., Vallribera, A., "Silica Aerogel-Iron Oxide Nanocomposites: Recoverable Catalysts in Conjugate Additions and in the Biginelli Reaction", Tetrahedron, 59, pp. 1553–1556, (2003).
[10]      Zhao, Y., Yinghua, L., Qianyi, J., Bobo, Z., "Preparation of CuO-CoO-MnO/SiO2 Nanocomposite Aerogels as Catalyst Carriers and Their Application in the Synthesis of Diphenyl Carbonate", Journal of Wuhan University of  Technology-Mater. Sci.
Ed., 26, pp. 595-599, (2011).
[11]      Maleki, H. Hüsing, N., "Current Status, Opportunities and Challenges in Catalytic and Photocatalytic Applications of Aerogels: Environmental Protection Aspects", Applied Catalysis B: Environmental, 221, pp. 530-555, (2018).
[12]      "Sol-Gel Process", in Handbook of Heterogeneous Catalysis 1, Ertl G., Knozinger H., Schuth, F., Weitkamp, J., Eds., 2 ed: Wiley-VCH Verlag GmbH & Co. KGaA, pp. 119-160, (2008).
[13]      Heinrichs, B., Lambert, S., Job, N., Pirard, J. -P., "Sol-Gel Synthesis of Supported Metals", in Catalyst Preparation: Science and Engineering, Regalbuto J., Ed., ed Boca Raton: CRC Press Taylor & Francis Group, pp. 163-208, (2007).
[14]      Shewale, P. M., Rao, A. V., Rao, A. P., "Effect of Different Trimethyl Silylating Agents on the Hydrophobic and Physical Properties of Silica Aerogels", Applied Surface Science, 254,
pp. 6902-6907, (2008).
[15]      Abdoli, S. M., Bastani, D., Bargozin, H., "Adsorption of Phenol Compounds by Nanoporous Silica Aerogel", Scientia Iranica, 22, pp. 992-1000 , (2015).
[16]      Roostaie, A., Bargozin, H., Mohammadiazar, S., Ehteshami, S., "Nanoporous Silica Aerogel Modified by Triethylchlorosilane as a New Sorbent for the Needle-Trap Extraction", Separation Eparation Science Plus, 1, pp. 76-82, (2018).
[17]      Aravind, P. R., Shajesh, P., Soraru, G. D., Warrier, K. G. K., "Ambient Pressure Drying: a Successful Approach for the Preparation of Silica and Silica Based Mixed Oxide Aerogels", Journal of Sol-Gel Science and Technology, 54, pp. 105–117, (2010).
[18]      Bhagat, S. D., Oh, C. -S., Kim, Y. -H., Ahn, Y. -S., Yeo, J. -G., "Methyltrimethoxysilane Based Monolithic Silica Aerogels via Ambient Pressure Drying", Microporous and Mesoporous Materials, 100, pp. 350-355, (2007).
 
 
 
 
[19]      Wu, G., Yu, Y., Cheng, X., Zhang, Y., "Preparation and Surface Modification Mechanism of Silica Aerogels via Ambient Pressure Drying", Materials Chemistry and Physics, 129, pp. 308-314, (2011).
[20]      Bargozin, H. Moghaddas, J. S., "Wettability Alteration with Silica Aerogel Nanodispersion", Journal of Dispersion Science and Technology, 34, pp. 1130-1138, (2013).
[21]      Bhagat, S. D., Kim, Y. -H., Ahn, Y. -S., Yeo, J. -G., "Textural Properties of Ambient Pressure Dried Water-Glass Based Silica Aerogel Beads: One Day Synthesis", Microporous and Mesoporous Materials, 96, pp. 237-244, (2006).
[22]      Popovici, M., Gich, M., Roig, A., Casas, L., Molins, E., Savii, C.,  Becherescu, D., Sort, J., Suriñach, S., Muñoz, J. S., Baró, M. D., Nogués, J., "Ultraporous Single Phase Iron Oxide-Silica Nanostructured Aerogels from Ferrous Precursors", Langmuir, 20,
pp. 1425-1429, (2004).
[23]      Popovici, M., Gigh, M., Savii, C., "Ultra-Light Sol-Gel Derived Magnetic Nanostructured Materials", Romanian Reports in Physics, 58, pp. 369–378, (2006).
[24]      Masoudian, S., Monfared, H. H., Aghaei, A., "Silica Aerogel–Iron Oxide Nanocomposites: Recoverable Catalysts for the Oxidation of Alcohols with Hydrogen Peroxide", Transition Metal Chemistry, 36, pp. 521-530, (2011).
[25]      Fabrizioli, P., Burgi, T., Burgener, M., Doorslaerb, S. V., Baiker, A., "Synthesis, Structural and Chemical Properties of Iron Oxide–Silica Aerogels", Journal of Materials Chemistry, 12, pp. 619–630, (2002).
[26]      Yousefi Amiri, T., Moghaddas, J. S., "Cogeled Copper–Silica Aerogel as a Catalyst in Hydrogen Production from Methanol Steam Reforming", International Journal of Hydrogen Energy, 40,
pp. 1472-1480, (2015).
[27]      Chorkendorff, I., Niemantsverdriet, J. W., Concepts of Modern Catalysis and Kinetics. Weinheim: WILEY-VCH, (2003).
[28]      Venkateswara Rao, A., Parvathy Rao, A., Kulkarni, M. M., "Influence of Gel Aging and Na2SiO3/H2O Molar Ratio on Monolithicity and Physical Properties of Water-Glass-Based Aerogels Dried at Atmospheric Pressure", Journal of Non-Crystalline Solids, 350, pp. 224-229, (2004).
[29]      Shi, F., Wang, L., Liu, J., "Synthesis and Characterization of Silica Aerogels by a Novel Fast Ambient Pressure Drying Process", Materials Letters, 60, pp. 3718-3722, (2006).
[30]      Bargozin, H., Amirkhani, L., Moghaddas, J. S., Ahadian, M. M., "Synthesis and Application of Silica Aerogel-MWCNT Nanocomposites for Adsorption of Organic Pollutants", Scientia Iranica, 17, pp. 122-132, (2010).
[31]      Ma, Z., Dunn, B. C., Turpin, G. C., Eyring, E. M., Ernst, R. D., Pugmire, R. J., "Solid State NMR Investigation of Silica Aerogel Supported Fischer–Tropsch Catalysts", Fuel Processing Technology, 88, pp. 29-33, (2007).
[32]      Zhao, Y., Liang, Y., Zhao, X., Li, H., Liu, X., "CuO-CoO-MnO/SiO2 Nanocomposite Aerogels as Catalysts Carrier and Effect of Process Factors on the Synthesis of Diphenyl Carbonate", Procedia Engineering, 27, pp. 1454-1461, (2012).
[33]      Zhao, Y. -Q., Liang, Y. -H., Zhao, X. -Z., Jia, Q. -Y., Li, H. -S., "Preparation and Microstructure of CuO-CoO-MnO/SiO2 Nanocomposite Aerogels and Xerogels as Catalyst Carriers", Progress in Natural Science: Materials International, 21, pp. 330-335, (2011).
[34]      Zhao, Y. -Q., Zhao, H. -L., Liang, Y. -H., Jia, Q. -Y., Zhang, B. -B., "Preparation and Characterization of CuO-CoO-MnO/SiO2 Nanocomposite Aerogels as Catalyst Carriers", Transactions of Nonferrous Metals Society of China, 20, pp. 1463-1469, (2010).
[35]      Orlovic, A., Janackovic, D., Skala, D., "Alumina/Silica Aerogel with Zinc Chloride Alkylation Catalyst: Influence of Supercritical Drying Conditions and Aerogel Structure on Alkylation Catalytic Activity", Catalysis Communications, 3,
pp. 119–123, (2002).
[36]      Moussa, N., Fraile, J. M., Ghorbel, A., Mayoral, J. A., "Catalytic Oxidation of Thioanisole Ph–S–CH3 Over VOx/SiO2 and VO /Al O Catalysts Prepared by Sol–Gel Method", Journal of Molecular Catalysis A: General, 255, pp. 62–68, (2006).
[37]      Moussa, N., Ghorbel, A., "UV–vis–DR Study of VOx/SiO2 Catalysts Prepared by Sol–Gel Method", Applied Surface Science, 225, pp. 2270–2275, (2008).
[38]      Choi, J., Shin, C. B., Suh, D. J., "Co-Promoted Pt Catalysts Supported on Silica Aerogel for Preferential Oxidation of CO", Catalysis Communications, 9,
pp. 880–885, (2008).
[39]      Somma, F., Puppinato, A., Strukul, G., "Niobia–Silica Aerogel Mixed Oxide Catalysts: Effects of the Niobium Content, the Calcination Temperature and the Surface Hydrophilicity on the Epoxidation of Olefins with Hydrogen Peroxide", Applied Catalysis A: General, 309, pp. 115–121, (2006).
[40]      Somma, F., Canton, P., Strukul, G., "Effect of the Matrix in Niobium-Based Aerogel Catalysts for the Selective Oxidation of Olefins with Hydrogen Peroxide", Journal of Catalysis, 229, pp. 490-498, (2005).
[41]      Somma, F., Strukul, G., "Niobium Containing Micro-, Meso- and Macroporous Silica Materials as Catalysts for the Epoxidation of Olefins with Hydrogen Peroxide", Catalysis Letters, 107, pp. 73-82, (2006).
[42]      Tai, Y., Murakami, J., Tajiri, K., Ohashi, F., Daté, M., Tsubota, S., "Oxidation of Carbon Monoxide on Au Nanoparticles in Titania and Titania-Coated Silica Aerogels", Applied Catalysis A: General, 268,
pp. 183–187, (2004).
[43]      Tai ,Y., Tajiri, K., "Preparation, Thermal Stability, and CO Oxidation Activity of Highly Loaded Au/Titania-Coated Silica Aerogel Catalysts", Applied Catalysis A: General, 342, pp. 113–118, (2008).
[44]      Tai, Y., Yamaguchi, W., Tajiri, K., Kageyama, H., "Structures and CO Oxidation Activities of Size-Selected Au Nanoparticles in Mesoporous Titania-Coated Silica Aerogels", Applied Catalysis A: General, 364, pp. 143-149, (2009).
[45]      Ling, L. S., Hamdan, H., "Sulfated Silica–Titania Aerogel as a Bifunctional Oxidative and Acidic Catalyst in the Synthesis of Diols", Journal of Non-Crystalline Solids, 354, pp. 3939–3943, (2008).
[46]      Akkariv, R., Ghorbel, A., Essayem, N., Figueras, F., "Sulfated Zirconia Grafted on a Mesoporous Silica Aerogel: Influence of the Preparation Parameters on Textural, Structural and Catalytic Properties", Microporous and Mesoporous Materials, 111,
pp. 62–71, (2008).
[47]      Wang, Y., Wu, R., Zhao, Y., "Effect of ZrO2 Promoter on Structure and Catalytic Activity of the Ni/SiO2 Catalyst for CO Methanation in Hydrogen-Rich Gases", Catalysis Today, 158, pp. 470–474, (2010).
[48]      Dutoit, D. C. M., Reiche, M. A., Baiker, A., "Vanadia-Silica Aerogels Structure and Catalytic Properties in Selective Reductionof NO by NH3 " Applied Catalysis B: Environmental, 13, pp. 275-288, (1997).
[49]      Yingxin, L., Zuojun, W., Jixiang, C., Jiyan, Z., "Effects of Preparation Methods of Support on the Properties of Nickel Catalyst for Hydrogenation of m-Dinitrobenzene", Front. Chem. Eng. China, 1,
pp. 287–291, (2007).
[50]      Cutrufello, M. G., Rombi, E., Ferino, I., Loche, D., Corrias, A., Casula, M. F., "Ni-Based Xero- and Aerogels as Catalysts for Nitroxidation Processes", Journal of Sol-Gel Science and Technology, 60,
pp. 324–332, (2011).
[51]      Silva, J. B., Mohallem, N. D. S., "Nanocomposites Based on Nickel Ferrites Dispersed in sol–gel Silica Matrices", Journal of Sol-Gel Science and Technology, 55, pp. 159–169, (2011).
[52]      Lee, S. L., Nur, H., Hamdan, H., "Physical Properties and Bifunctional Catalytic Performance of Phosphate–Vanadium Impregnated Silica–Titania Aerogel", Catalysis Letter, 132, pp. 28–33, (2009).
[53]      Kim, W. -I., Suh, D. J., Park, T. -J., Hong, I. -K., "Photocatalytic Degradation of Methanol on Titania and Titania–Silica Aerogels Prepared by Non-alkoxide Sol–Gel Route", Topics in Catalysis, 44,
pp. 499-506, (2007).
[54]      Ingale, S. V., Wagh, P. B., Tripathi, A. K., Dudwadkar, A. S., Gamre, S. S., Rao, P. T., Singh, I. K., Gupta, S. C.",Photo Catalytic Oxidation of TNT Using TiO2-SiO2 Nano-Composite Aerogel Catalyst Prepared Using Sol–Gel Process", Journal of Sol-Gel Science and Technology, 58, pp. 682–688, (2011).
[55]      Beck, C., Mallat, T., Baiker, A., "Oxidation–Isomerization of an Olefin to Allylic Alcohol Using Titania–Silica and a Base Co-catalyst", Journal of Catalysis, 195, pp. 79–87, (2000).
[56]      Miller, J. B., Rankin, S. E., Ko, E. I., "Strategies in Controlling the Homogeneity of Zirconia-Silica Aerogels: Effect of Preparation on Textural and Catalytic Properties", Journal of Catalysis, 148,
pp. 673-682, (1994).
[57]      Zou, W., Gonzalez, R. D., "The Preparation of High-Surface-Area Pt/SiO2 Catalysts with Well-Defined Pore Size Distributions", Journal of Catalysis, 152, pp. 291-305, (1995).
[58]      Heinrichs, B., Noville, F., Pirard, J. -P., "Pd/SiO2-Cogelled Aerogel Catalysts and Impregnated Aerogel and Xerogel Catalysts: Synthesis and Characterization", Journal of Catalysis, 170,
pp. 366–376, (1997).
[59]      Cauqui, M. A., Calvino, J. J., Cifredo, G., Esquivias, L., Rodrlguez-Izquierdo, J. M., "Preparation of Rhodium Catalysts Dispersed on TiO2-SiO2 Aerogels " Journal of Non-Crystalline Solids, 148, pp. 758-763, (1992).
[60]      Klvana, D., Chaouki, J., Kusohorsky, D., Chavarie, C., "Catalytic Storage of Hydrogen: Hydrogenation of Toluene over a Nickel/Silica Aerogel Catalyst in Integral Flow Conditions " Applied Catalysis, 42,
pp. 121-130, (1988).
[61]      Maurer, S. M., Ko, E. I., "Synthesis and Characterization of Niobia-Containing Aerogels " Catalysis Letters, 12, pp. 231-238, (1992).
[62]      Owens, L., Tillotson, T. M., Hair, L. M., "Characterization of Vanadium/Silica and Copper/Silica Aerogel Catalysts " Journal of Non-Crystalline Solids, 186, pp. 177-183, (1995).
[63]      Hair, L. M., Owens, L., Tillotson, T., Froba, M., Wong, J., Thomas, G. J., Medlin, D. L., "Local, Nano- and Micro-Structures of Mixed Metal Oxide Aerogels for Catalyst Applications", Journal of Non-Crystalline Solids, 186, pp. 168-176, (1995).
[64]      Hutter, R., Mallat, T., Baiker, A., "Titania-Silica Mixed Oxides: III. Epoxidation of α-Isophorone with Hydroperoxides", Journal of Catalysis, 157,
pp. 665-675, (1995).
[65]      Dutoit, D. C. M., Schneider, M., Hutter, R., Baiker, A., "Titania–Silica Mixed Oxides: IV. Influence of Ti Content and Aging on Structural and Catalytic Properties of Aerogels", Journal of Catalysis, 161,
pp. 651-658, (1996).
[66]      Müller, C. A., Schneider, M. S., Mallat, T., Baiker, A., "Epoxidation of α-Isophorone with Amine-Modified Titania-Silica Hybrid Aerogel: Evidence for Ti-amine Interaction", Journal of Catalysis, 192,
pp. 448-451, (2000).
[67]      Hutter, R., Mallat, T., Peterhans, A., Baiker, A., "Epoxidation of β-Isophorone over a Titania–Silica Aerogel: Effect of Catalyst Pretreatments with Bases", Journal of Catalysis, 172, pp. 427-435, (1997).
[68]      Cao, S., Yeung, K. L., Yue, P. -L., "Preparation of Freestanding and Crack-Free Titania–Silica Aerogels and Their Performance for Gas Phase, Photocatalytic Oxidation of VOCs", Applied Catalysis B: Environmental, 68, pp. 99-108, (2006).
[69]      Cao, S., Yeung, K. L., Yue, P. -L., "An Investigation of Trichloroethylene Photocatalytic Oxidation on Mesoporous Titania-Silica Aerogel Catalysts", Applied Catalysis B: Environmental, 76, pp. 64-72, (2007).
[70]      Yoon, J. S., Lee, Y., Ryu, J., Kim, Y. -A., Park, E. D., Choi, J.-W., Ha, J. -M.,Suh, D. J.,Lee, H., "Production of High Carbon Number Hydrocarbon Fuels from a Lignin-Derived α-O-4 Phenolic Dimer, Benzyl Phenyl Ether, via Isomerization of Ether to Alcohols on High-Surface-Area Silica-Alumina Aerogel Catalysts", Applied Catalysis B: Environmental, 142-143, pp. 668-676, (2013).
[71]      Ryu, J., Kim, S. M., Choi, J. -W., Ha, J. -M., Ahn, D. J., Suh, D. J., Suh, Y. W., "Highly Durable Pt-Supported Niobia–Silica Aerogel Catalysts in the Aqueous-Phase Hydrodeoxygenation of 1-Propanol", Catalysis Communications, 29, pp. 40-47, (2012).
[72]      Wijaya, Y. P., Suh, D. J., Jae, J., "Production of Renewable p-Xylene from 2,5-Dimethylfuran via Diels–Alder Cycloaddition and Dehydrative Aromatization Reactions over Silica−Alumina Aerogel Catalysts", Catalysis Communications, 70, pp. 12-16, (2015).
[73]      Gisler, A., Bürgi, T., Baiker, A., "Epoxidation of Cyclic Allylic Alcohols on Titania–Silica Aerogels Studied by Attenuated Total Reflection Infrared and Modulation Spectroscopy", Journal of Catalysis, 222, pp. 461-469, (2004).
[74]      Peiris Weerasinghe, M. N., Klabunde, K. J., "Chromium Oxide Loaded Silica Aerogels: Novel Visible Light Photocatalytic Materials for Environmental Remediation", Journal of Photochemistry and Photobiology A: Chemistry, 254, pp. 62-70, (2013).
[75]      Bereczki, H. F., Daróczi, L., Fábián, I., Lázár, I., "Sol-gel Synthesis, Characterization and Catalytic Activity of Silica Aerogels Functionalized with Copper(II) Complexes of Cyclen and Cyclam", Microporous and Mesoporous Materials, 234,
pp. 392-400, (2016).
[76]      Kantam, M. L., Rao, B. P. C., Reddy, R. S., Sekhar, N. S., Sreedhar, B., Choudary, B. M., "Aerobic Epoxidation of Olefins Catalyzed by Co-SiO2 Nanocomposites", Journal of Molecular Catalysis A: Chemical, 272, pp. 1-5, (2007).
[77]      Hair, L. M., Coronado, P. R., Reynolds, J. G., "Mixed-metal Oxide Aerogels for Oxidation of Volatile Organic Compounds", Journal of Non-Crystalline Solids, 270, pp. 115-122, (2000).
[78]      Wang, C. -T., Willey, R. J., "Oxidation of Methanol over Iron Oxide Based Aerogels in Supercritical CO2", Journal of Non-Crystalline Solids, 225,
pp. 173-177, (1998).
[79]      Gisler, A., Müller, C. A., Schneider, M., Mallat, T., Baiker, A., "Synthesis of Organically Modified Titania-Silica Aerogels: Application for Epoxidation of Cyclohexenol", in Studies in Surface Science and Catalysis. 130, A. Corma, F. V. Melo, S. Mendioroz, and J. L. G. Fierro, Eds., ed: Elsevier, pp. 1637-1642, (2000).
[80]      Blanchard, F., Pommier, B., Reymond, J. P., Teichner, S. J., "New Fischer-Tropsch Catalysts Of The Aerogel Type", in Studies in Surface Science and Catalysis. 16, G. Poncelet, P. Grange, and P. A. Jacobs, Eds., ed: Elsevier, pp. 395-407, (1983).
[81]      Hutter, R., Mallat, T., Baiker, A., "Epoxidation of Cycloalkenones over Amorphous Titania-Silica Aerogels", in Studies in Surface Science and Catalysis. 108, H. U. Blaser, A. Baiker, and R. Prins, Eds., ed: Elsevier, pp. 329-336, (1997).
[82]      Wildberger, M. D., Mallat, T., Göbel, U., Baiker, A., "Oxidation of Butane and Butadiene to Furan over Vanadia–Silica Mixed Oxides", Applied Catalysis A: General, 168, pp. 69-80, (1998).
[83]      Malinowska, B., Walendziewski, J., Robert, D., Weber, J. V., Stolarski, M., "The Study of Photocatalytic Activities of Titania and Titania–Silica Aerogels", Applied Catalysis B: Environmental, 46, pp. 441-451, (2003).
[84]      Reiche, M. A., Ortelli, E.,, Baiker, A., "Vanadia Grafted on TiO2–SiO2, TiO2 and SiO2 Aerogels: Structural Properties and Catalytic Behaviour in Selective Reduction of NO by NH3", Applied Catalysis B: Environmental, 23, pp.187-203, (1999).
[85]      Dusi, M., Mallat, T., Baiker, A., "Chemo- and Diastereoselective Epoxidation of Allylic Alcohols with a Titania–Silica Aerogel", Journal of Molecular Catalysis A: Chemical, 138, pp. 15-23, (1999).
[86]      Yi, Z., Zhao, S., Zhang, J., She, M. F., Kong, L., Dumée, L. F., "Discrete Silver Nanoparticle Infusion Across Silica Aerogels Towards Versatile Catalytic Coatings for 4-Nitrophenol Reduction", Materials Chemistry and Physics, 223, pp. 404-40, (2019).
[87]      Lázár, I., Kalmár, J., Peter, A., Szilágyi, A., Győri, E., Ditrói, T., Fábián, I., "Photocatalytic Performance of Highly Amorphous Titania–Silica Aerogels with Mesopores: The Adverse Effect of the in Situ Adsorption of Some Organic Substrates During Photodegradation", Applied Surface Science, 356,
pp. 521-531, (2015).
[88]      Feng, X., Wang, L., Yao, X., Dong, H., Wang, X., Wang, Y., "Trace Water/Amino-Modified Silica Aerogel Catalytic System in the One-Pot Sequential Reaction of Benzaldehyde Dimethyl Acetal and Nitromethane", Catalysis Communications, 90,
pp. 106-110, (2017).
[89]      Sanz-Moral, L. M., Romero, A., Holz, F., Rueda, M., Navarrete, A., Martín, A., "Tuned Pd/SiO2 Aerogel Catalyst Prepared by Different Synthesis Techniques", Journal of the Taiwan Institute of Chemical Engineers, 65, pp. 515-521, (2016).
[90]      Long, T., Xu, Y., Lv, X., Ran, J., Yang, S., Xu, L., "Fabrication of the Annular Photocatalytic Reactor Using Large-Sized Freestanding Titania-Silica Monolithic Aerogel as the Catalyst for Degradation of Glyphosate", Materials & Design, 159, pp. 195-200, (2018).
[91]      Yousefi Amiri, T., Moghaddas, J. S., "Reaction Parameters Influence on the Catalytic Performance of Copper-Silica Aerogel in the Methanol Steam Reforming", Journal of Fuel Chemistry and Technology, 44, pp. 84-90, (2016).
 
[92]      Yousefi Amiri, T., Moghaddas, J. S., "Performance Evaluation of Cu-SiO2 Aerogel Catalyst in Methanol Steam Reforming", Iranian Journal of Chemical Engineering, 11, pp. 37-44, (2014).
[93]      Ferreira-Neto, E. P., Worsley, M. A., Rodrigues-Filho, U. P., "Towards thermally stable aerogel photocatalysts: TiCl4-based sol-gel routes for the design of nanostructured silica-titania aerogel with high photocatalytic activity and outstanding thermal stability", Journal of Environmental Chemical Engineering, 7, p. 103425, (2019).
[94]      Parale, V. G., Kim, T., Lee, K. Y., Phadtare, V. D., Dhavale, R. P., Jung, H. N. R., Park, H. H., "Hydrophobic TiO2–SiO2 composite aerogels synthesized via in situ epoxy-ring opening polymerization and sol-gel process for enhanced degradation activity", Ceramics International, 46,
pp. 4939-4946, (2020).
[95]      Posada, L. F., Carroll, M. K., Anderson, A. N., Bruno, B. A., "Inclusion of Ceria in Alumina- and Silica-Based Aerogels for Catalytic Applications", Journal of Supercritical Fluids, 152, p. 104536, (2019).